Enciclopedia de yates
Moisture meter (hull survey)
Moisture meters on GRP yachts: what surveyors measure, how FairHelm reads maps, and limits of single spot readings.
Qué es
A moisture meter in yacht survey work is an instrument that estimates relative moisture in GRP laminate, gelcoat, or sandwich core, usually by capacitance or resistance methods.
Anchor
FairHelm survey language on Baltic boats often includes a moisture map of underwater sections after haul-out and drying time. Deck and coachroof cores need separate attention from hull bottom readings.
FairHelm judgment
FairHelm judgment: one high spot without context is weak evidence. Ask when the boat was hauled, washed, and measured, which scale the meter used, and whether readings cluster. Compare to known dry reference panels on the same boat.
Limits
Meters do not give absolute water percent for every laminate. Coatings, temperature, and meter type change numbers. They guide further checks; they do not replace core samples or ultrasound when those are justified.
Preguntas frecuentes
Q: Does a high reading always mean osmosis?
A: No. It means investigate. Blisters, core moisture, and meter error are different paths.
Q: Can I trust seller phone photos of a meter?
A: Weakly. Prefer a surveyor map with conditions noted.
Q: Should decks use the same meter as the hull?
A: Often yes as a tool, but interpret core decks separately from solid hull bottoms.